javaslang.collection.CharSeq Maven / Gradle / Ivy
/* / \____ _ _ ____ ______ / \ ____ __ _______
* / / \/ \ / \/ \ / /\__\/ // \/ \ // /\__\ JΛVΛSLΛNG
* _/ / /\ \ \/ / /\ \\__\\ \ // /\ \ /\\/ \ /__\ \ Copyright 2014-2016 Javaslang, http://javaslang.io
* /___/\_/ \_/\____/\_/ \_/\__\/__/\__\_/ \_// \__/\_____/ Licensed under the Apache License, Version 2.0
*/
package javaslang.collection;
import javaslang.*;
import javaslang.collection.CharSeqModule.Combinations;
import javaslang.control.Option;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.*;
import java.util.HashSet;
import java.util.function.*;
import java.util.regex.PatternSyntaxException;
import java.util.stream.Collector;
/**
* The CharSeq (read: character sequence) collection essentially is a rich String wrapper having all operations
* we know from the functional Javaslang collections.
*
* @author Ruslan Sennov, Daniel Dietrich
* @since 2.0.0
*/
public final class CharSeq implements Kind1, CharSequence, IndexedSeq, Serializable {
private static final long serialVersionUID = 1L;
private static final CharSeq EMPTY = new CharSeq("");
private final String back;
private CharSeq(String javaString) {
this.back = javaString;
}
public static CharSeq empty() {
return EMPTY;
}
/**
* Returns a {@link java.util.stream.Collector} which may be used in conjunction with
* {@link java.util.stream.Stream#collect(java.util.stream.Collector)} to obtain a {@link CharSeq}.
*
* @return A {@code CharSeq} Collector.
*/
public static Collector, CharSeq> collector() {
final Supplier> supplier = ArrayList::new;
final BiConsumer, Character> accumulator = ArrayList::add;
final BinaryOperator> combiner = (left, right) -> {
left.addAll(right);
return left;
};
final Function, CharSeq> finisher = CharSeq::ofAll;
return Collector.of(supplier, accumulator, combiner, finisher);
}
/**
* Creates a String of {@code CharSequence}.
*
* @param sequence {@code CharSequence} instance.
* @return A new {@code javaslang.String}
*/
// DEV-NOTE: Needs to be 'of' instead of 'ofAll' because 'ofAll(CharSeq)' is ambiguous.
public static CharSeq of(CharSequence sequence) {
Objects.requireNonNull(sequence, "sequence is null");
if (sequence instanceof CharSeq) {
return (CharSeq) sequence;
} else {
return sequence.length() == 0 ? empty() : new CharSeq(sequence.toString());
}
}
/**
* Returns a singleton {@code CharSeq}, i.e. a {@code CharSeq} of one character.
*
* @param character A character.
* @return A new {@code CharSeq} instance containing the given element
*/
public static CharSeq of(char character) {
return new CharSeq(new String(new char[] { character }));
}
/**
* Creates a String of the given characters.
*
* @param characters Zero or more characters.
* @return A string containing the given characters in the same order.
* @throws NullPointerException if {@code elements} is null
*/
public static CharSeq of(char... characters) {
Objects.requireNonNull(characters, "characters is null");
if (characters.length == 0) {
return empty();
} else {
final char[] chrs = new char[characters.length];
System.arraycopy(characters, 0, chrs, 0, characters.length);
return new CharSeq(new String(chrs));
}
}
/**
* Creates a String of the given elements.
*
* The resulting string has the same iteration order as the given iterable of elements
* if the iteration order of the elements is stable.
*
* @param elements An Iterable of elements.
* @return A string containing the given elements in the same order.
* @throws NullPointerException if {@code elements} is null
*/
public static CharSeq ofAll(Iterable elements) {
Objects.requireNonNull(elements, "elements is null");
final StringBuilder sb = new StringBuilder();
for (Character character : elements) {
sb.append(character);
}
return sb.length() == 0 ? EMPTY : of(sb.toString());
}
/**
* Returns a CharSeq containing {@code n} values of a given Function {@code f}
* over a range of integer values from 0 to {@code n - 1}.
*
* @param n The number of elements in the CharSeq
* @param f The Function computing element values
* @return A CharSeq consisting of elements {@code f(0),f(1), ..., f(n - 1)}
* @throws NullPointerException if {@code f} is null
*/
public static CharSeq tabulate(int n, Function f) {
Objects.requireNonNull(f, "f is null");
StringBuilder sb = new StringBuilder();
for (int i = 0; i < n; i++) {
sb.append(f.apply(i));
}
return of(sb);
}
/**
* Returns a CharSeq containing {@code n} values supplied by a given Supplier {@code s}.
*
* @param n The number of elements in the CharSeq
* @param s The Supplier computing element values
* @return A CharSeq of size {@code n}, where each element contains the result supplied by {@code s}.
* @throws NullPointerException if {@code s} is null
*/
public static CharSeq fill(int n, Supplier s) {
return tabulate(n, anything -> s.get());
}
/**
* Creates a CharSeq starting from character {@code from}, extending to character {@code toExclusive - 1}.
*
* Examples:
*
*
* CharSeq.range('a', 'c') // = "ab"
* CharSeq.range('c', 'a') // = ""
*
*
*
* @param from the first character
* @param toExclusive the successor of the last character
* @return a range of characters as specified or the empty range if {@code from >= toExclusive}
*/
public static CharSeq range(char from, char toExclusive) {
return new CharSeq(Iterator.range(from, toExclusive).mkString());
}
public static CharSeq rangeBy(char from, char toExclusive, int step) {
return new CharSeq(Iterator.rangeBy(from, toExclusive, step).mkString());
}
/**
* Creates a CharSeq starting from character {@code from}, extending to character {@code toInclusive}.
*
* Examples:
*
*
* CharSeq.rangeClosed('a', 'c') // = "abc"
* CharSeq.rangeClosed('c', 'a') // = ""
*
*
*
* @param from the first character
* @param toInclusive the last character
* @return a range of characters as specified or the empty range if {@code from > toInclusive}
*/
public static CharSeq rangeClosed(char from, char toInclusive) {
return new CharSeq(Iterator.rangeClosed(from, toInclusive).mkString());
}
/**
* Creates a CharSeq starting from character {@code from}, extending to character {@code toInclusive},
* with {@code step}.
*
* Examples:
*
*
* CharSeq.rangeClosedBy('a', 'c', 1) // = ('a', 'b', 'c')
* CharSeq.rangeClosedBy('a', 'd', 2) // = ('a', 'c')
* CharSeq.rangeClosedBy('d', 'a', -2) // = ('d', 'b')
* CharSeq.rangeClosedBy('d', 'a', 2) // = ()
*
*
*
* @param from the first character
* @param toInclusive the last character
* @param step the step
* @return a range of characters as specified or the empty range if {@code step * (from - toInclusive) > 0}.
* @throws IllegalArgumentException if {@code step} is zero
*/
public static CharSeq rangeClosedBy(char from, char toInclusive, int step) {
return new CharSeq(Iterator.rangeClosedBy(from, toInclusive, step).mkString());
}
private Tuple2 splitByBuilder(StringBuilder sb) {
if (sb.length() == 0) {
return Tuple.of(EMPTY, this);
} else if (sb.length() == length()) {
return Tuple.of(this, EMPTY);
} else {
return Tuple.of(of(sb.toString()), of(back.substring(sb.length())));
}
}
/**
* Repeats a character {@code times} times.
*
* @param character A character
* @param times Repetition count
* @return A CharSeq representing {@code character * times}
*/
public static CharSeq repeat(char character, int times) {
final int length = Math.max(times, 0);
final char[] characters = new char[length];
Arrays.fill(characters, character);
return new CharSeq(String.valueOf(characters));
}
/**
* Repeats this CharSeq {@code times} times.
*
* Example: {@code CharSeq.of("ja").repeat(13) = "jajajajajajajajajajajajaja"}
*
* @param times Repetition count
* @return A CharSeq representing {@code this * times}
*/
public CharSeq repeat(int times) {
final StringBuilder builder = new StringBuilder();
for (int i = 0; i < times; i++) {
builder.append(back);
}
return new CharSeq(builder.toString());
}
//
//
// IndexedSeq
//
//
@Override
public CharSeq append(Character element) {
return of(back + element);
}
@Override
public CharSeq appendAll(Iterable elements) {
Objects.requireNonNull(elements, "elements is null");
final StringBuilder sb = new StringBuilder(back);
for (char element : elements) {
sb.append(element);
}
return of(sb.toString());
}
@Override
public IndexedSeq combinations() {
return Vector.rangeClosed(0, length()).map(this::combinations).flatMap(Function.identity());
}
@Override
public IndexedSeq combinations(int k) {
return Combinations.apply(this, Math.max(k, 0));
}
@Override
public Iterator crossProduct(int power) {
return Collections.crossProduct(CharSeq.empty(), this, power);
}
@Override
public CharSeq distinct() {
return distinctBy(Function.identity());
}
@Override
public CharSeq distinctBy(Comparator comparator) {
Objects.requireNonNull(comparator, "comparator is null");
final java.util.Set seen = new java.util.TreeSet<>(comparator);
return filter(seen::add);
}
@Override
public CharSeq distinctBy(Function keyExtractor) {
Objects.requireNonNull(keyExtractor, "keyExtractor is null");
final java.util.Set seen = new java.util.HashSet<>();
return filter(t -> seen.add(keyExtractor.apply(t)));
}
@Override
public CharSeq drop(long n) {
if (n <= 0) {
return this;
} else if (n >= length()) {
return EMPTY;
} else {
return of(back.substring((int) n));
}
}
@Override
public CharSeq dropRight(long n) {
if (n <= 0) {
return this;
} else if (n >= length()) {
return EMPTY;
} else {
return of(back.substring(0, length() - (int) n));
}
}
@Override
public CharSeq dropUntil(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
return dropWhile(predicate.negate());
}
@Override
public CharSeq dropWhile(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
int index = 0;
while (index < length() && predicate.test(charAt(index))) {
index++;
}
return index < length() ? (index == 0 ? this : of(back.substring(index))) : empty();
}
@Override
public CharSeq filter(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
final StringBuilder sb = new StringBuilder();
for (int i = 0; i < back.length(); i++) {
final char ch = back.charAt(i);
if (predicate.test(ch)) {
sb.append(ch);
}
}
return sb.length() == 0 ? EMPTY : sb.length() == length() ? this : of(sb.toString());
}
@Override
public IndexedSeq flatMap(Function> mapper) {
Objects.requireNonNull(mapper, "mapper is null");
if (isEmpty()) {
return Vector.empty();
} else {
IndexedSeq result = Vector.empty();
for (int i = 0; i < length(); i++) {
for (U u : mapper.apply(get(i))) {
result = result.append(u);
}
}
return result;
}
}
public CharSeq flatMapChars(CharFunction mapper) {
Objects.requireNonNull(mapper, "mapper is null");
if (isEmpty()) {
return this;
} else {
final StringBuilder builder = new StringBuilder();
back.chars().forEach(c -> builder.append(mapper.apply((char) c)));
return new CharSeq(builder.toString());
}
}
@Override
public Map groupBy(Function classifier) {
Objects.requireNonNull(classifier, "classifier is null");
return iterator().groupBy(classifier).map((c, it) -> Tuple.of(c, CharSeq.ofAll(it)));
}
@Override
public Iterator grouped(long size) {
return sliding(size, size);
}
@Override
public boolean hasDefiniteSize() {
return true;
}
@Override
public CharSeq init() {
if (isEmpty()) {
throw new UnsupportedOperationException("init of empty string");
} else {
return of(back.substring(0, length() - 1));
}
}
@Override
public Option initOption() {
return isEmpty() ? Option.none() : Option.some(init());
}
@Override
public CharSeq insert(int index, Character element) {
if (index < 0) {
throw new IndexOutOfBoundsException("insert(" + index + ", e)");
}
if (index > length()) {
throw new IndexOutOfBoundsException("insert(" + index + ", e) on String of length " + length());
}
return of(new StringBuilder(back).insert(index, element).toString());
}
@Override
public CharSeq insertAll(int index, Iterable elements) {
Objects.requireNonNull(elements, "elements is null");
if (index < 0) {
throw new IndexOutOfBoundsException("insertAll(" + index + ", elements)");
}
if (index > length()) {
throw new IndexOutOfBoundsException("insertAll(" + index + ", elements) on String of length " + length());
}
final String javaString = back;
final StringBuilder sb = new StringBuilder(javaString.substring(0, index));
for (Character element : elements) {
sb.append(element);
}
sb.append(javaString.substring(index));
return of(sb.toString());
}
@Override
public Iterator iterator() {
return new AbstractIterator() {
private int index = 0;
@Override
public boolean hasNext() {
return index < back.length();
}
@Override
public Character getNext() {
return back.charAt(index++);
}
};
}
@Override
public CharSeq intersperse(Character element) {
final StringBuilder sb = new StringBuilder();
for (int i = 0; i < length(); i++) {
if (i > 0) {
sb.append(element);
}
sb.append(get(i));
}
return sb.length() == 0 ? EMPTY : of(sb.toString());
}
@Override
public IndexedSeq map(Function mapper) {
Objects.requireNonNull(mapper, "mapper is null");
IndexedSeq result = Vector.empty();
for (int i = 0; i < length(); i++) {
result = result.append(mapper.apply(get(i)));
}
return result;
}
@Override
public CharSeq padTo(int length, Character element) {
if (length <= back.length()) {
return this;
}
final StringBuilder sb = new StringBuilder(back);
final int limit = length - back.length();
for (int i = 0; i < limit; i++) {
sb.append(element);
}
return new CharSeq(sb.toString());
}
@Override
public CharSeq patch(int from, Iterable that, int replaced) {
from = from < 0 ? 0 : from > length() ? length() : from;
replaced = replaced < 0 ? 0 : replaced;
final StringBuilder sb = new StringBuilder(back.substring(0, from));
for (Character character : that) {
sb.append(character);
}
from += replaced;
if (from < length()) {
sb.append(back.substring(from));
}
return sb.length() == 0 ? EMPTY : new CharSeq(sb.toString());
}
public CharSeq mapChars(CharUnaryOperator mapper) {
Objects.requireNonNull(mapper, "mapper is null");
if (isEmpty()) {
return this;
} else {
final char[] chars = back.toCharArray();
for (int i = 0; i < chars.length; i++) {
chars[i] = mapper.apply(chars[i]);
}
return CharSeq.of(chars);
}
}
@Override
public Tuple2 partition(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
if (isEmpty()) {
return Tuple.of(EMPTY, EMPTY);
}
final StringBuilder left = new StringBuilder();
final StringBuilder right = new StringBuilder();
for (int i = 0; i < length(); i++) {
Character t = get(i);
(predicate.test(t) ? left : right).append(t);
}
if (left.length() == 0) {
return Tuple.of(EMPTY, of(right.toString()));
} else if (right.length() == 0) {
return Tuple.of(of(left.toString()), EMPTY);
} else {
return Tuple.of(of(left.toString()), of(right.toString()));
}
}
@Override
public CharSeq peek(Consumer action) {
Objects.requireNonNull(action, "action is null");
if (!isEmpty()) {
action.accept(back.charAt(0));
}
return this;
}
@Override
public IndexedSeq permutations() {
if (isEmpty()) {
return Vector.empty();
} else {
if (length() == 1) {
return Vector.of(this);
} else {
IndexedSeq result = Vector.empty();
for (Character t : distinct()) {
for (CharSeq ts : remove(t).permutations()) {
result = result.append(CharSeq.of(t).appendAll(ts));
}
}
return result;
}
}
}
@Override
public CharSeq prepend(Character element) {
return of(element + back);
}
@Override
public CharSeq prependAll(Iterable elements) {
Objects.requireNonNull(elements, "elements is null");
final StringBuilder sb = new StringBuilder();
for (Character element : elements) {
sb.append(element);
}
sb.append(back);
return sb.length() == 0 ? EMPTY : of(sb.toString());
}
@Override
public CharSeq remove(Character element) {
final StringBuilder sb = new StringBuilder();
boolean found = false;
for (int i = 0; i < length(); i++) {
char c = get(i);
if (!found && c == element) {
found = true;
} else {
sb.append(c);
}
}
return sb.length() == 0 ? EMPTY : sb.length() == length() ? this : of(sb.toString());
}
@Override
public CharSeq removeFirst(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
final StringBuilder sb = new StringBuilder();
boolean found = false;
for (int i = 0; i < back.length(); i++) {
final char ch = back.charAt(i);
if (predicate.test(ch)) {
if (found) {
sb.append(ch);
}
found = true;
} else {
sb.append(ch);
}
}
return found ? (sb.length() == 0 ? EMPTY : of(sb.toString())) : this;
}
@Override
public CharSeq removeLast(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
for (int i = length() - 1; i >= 0; i--) {
if (predicate.test(back.charAt(i))) {
return removeAt(i);
}
}
return this;
}
@Override
public CharSeq removeAt(int index) {
final String removed = back.substring(0, index) + back.substring(index + 1);
return removed.isEmpty() ? EMPTY : of(removed);
}
@Override
public CharSeq removeAll(Character element) {
final StringBuilder sb = new StringBuilder();
for (int i = 0; i < length(); i++) {
final char c = back.charAt(i);
if (c != element) {
sb.append(c);
}
}
return sb.length() == 0 ? EMPTY : sb.length() == length() ? this : of(sb.toString());
}
@Override
public CharSeq removeAll(Iterable elements) {
Objects.requireNonNull(elements, "elements is null");
final java.util.Set distinct = new HashSet<>();
for (Character element : elements) {
distinct.add(element);
}
final StringBuilder sb = new StringBuilder();
for (int i = 0; i < length(); i++) {
final char c = back.charAt(i);
if (!distinct.contains(c)) {
sb.append(c);
}
}
return sb.length() == 0 ? EMPTY : sb.length() == length() ? this : of(sb.toString());
}
@Override
public CharSeq replace(Character currentElement, Character newElement) {
final StringBuilder sb = new StringBuilder();
boolean found = false;
for (int i = 0; i < length(); i++) {
final char c = back.charAt(i);
if (c == currentElement && !found) {
sb.append(newElement);
found = true;
} else {
sb.append(c);
}
}
return found ? of(sb.toString()) : this;
}
@Override
public CharSeq replaceAll(Character currentElement, Character newElement) {
final StringBuilder sb = new StringBuilder();
boolean found = false;
for (int i = 0; i < length(); i++) {
final char c = back.charAt(i);
if (c == currentElement) {
sb.append(newElement);
found = true;
} else {
sb.append(c);
}
}
return found ? of(sb.toString()) : this;
}
@Override
public CharSeq retainAll(Iterable elements) {
Objects.requireNonNull(elements, "elements is null");
final java.util.Set kept = new HashSet<>();
for (Character element : elements) {
kept.add(element);
}
final StringBuilder sb = new StringBuilder();
for (int i = 0; i < length(); i++) {
final char c = back.charAt(i);
if (kept.contains(c)) {
sb.append(c);
}
}
return sb.length() == 0 ? EMPTY : of(sb.toString());
}
@Override
public CharSeq reverse() {
return of(new StringBuilder(back).reverse().toString());
}
@Override
public IndexedSeq scan(Character zero, BiFunction operation) {
return scanLeft(zero, operation);
}
@Override
public IndexedSeq scanLeft(U zero, BiFunction operation) {
Objects.requireNonNull(operation, "operation is null");
return Collections.scanLeft(this, zero, operation, Vector.empty(), Vector::append, Function.identity());
}
@Override
public IndexedSeq scanRight(U zero, BiFunction operation) {
Objects.requireNonNull(operation, "operation is null");
return Collections.scanRight(this, zero, operation, Vector.empty(), Vector::prepend, Function.identity());
}
@Override
public CharSeq slice(long beginIndex, long endIndex) {
final long from = beginIndex < 0 ? 0 : beginIndex;
final long to = endIndex > length() ? length() : endIndex;
if (from >= to) {
return EMPTY;
}
if (from <= 0 && to >= length()) {
return this;
}
return CharSeq.of(back.substring((int) from, (int) to));
}
@Override
public Iterator sliding(long size) {
return sliding(size, 1);
}
@Override
public Iterator sliding(long size, long step) {
return iterator().sliding(size, step).map(CharSeq::ofAll);
}
@Override
public CharSeq sorted() {
return isEmpty() ? this : toJavaStream().sorted().collect(CharSeq.collector());
}
@Override
public CharSeq sorted(Comparator comparator) {
Objects.requireNonNull(comparator, "comparator is null");
return isEmpty() ? this : toJavaStream().sorted(comparator).collect(CharSeq.collector());
}
@Override
public > CharSeq sortBy(Function mapper) {
return sortBy(U::compareTo, mapper);
}
@Override
public CharSeq sortBy(Comparator comparator, Function mapper) {
final Function domain = Function1.of(mapper::apply).memoized();
return toJavaStream()
.sorted((e1, e2) -> comparator.compare(domain.apply(e1), domain.apply(e2)))
.collect(collector());
}
@Override
public Tuple2 span(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
final StringBuilder sb = new StringBuilder();
for (int i = 0; i < length(); i++) {
final char c = back.charAt(i);
if (predicate.test(c)) {
sb.append(c);
} else {
break;
}
}
return splitByBuilder(sb);
}
@Override
public Spliterator spliterator() {
return Spliterators.spliterator(iterator(), length(), Spliterator.ORDERED | Spliterator.IMMUTABLE);
}
@Override
public CharSeq subSequence(int beginIndex) {
if (beginIndex < 0 || beginIndex > length()) {
throw new IndexOutOfBoundsException("begin index " + beginIndex + " < 0");
}
if (beginIndex == 0) {
return this;
} else if (beginIndex == length()) {
return EMPTY;
} else {
return CharSeq.of(back.substring(beginIndex));
}
}
@Override
public CharSeq tail() {
if (isEmpty()) {
throw new UnsupportedOperationException("tail of empty string");
} else {
return CharSeq.of(back.substring(1));
}
}
@Override
public Option tailOption() {
return isEmpty() ? Option.none() : Option.some(tail());
}
@Override
public CharSeq take(long n) {
if (n <= 0) {
return EMPTY;
} else if (n >= length()) {
return this;
} else {
return CharSeq.of(back.substring(0, (int) n));
}
}
@Override
public CharSeq takeRight(long n) {
if (n <= 0) {
return EMPTY;
} else if (n >= length()) {
return this;
} else {
return CharSeq.of(back.substring(length() - (int) n));
}
}
@Override
public CharSeq takeUntil(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
return takeWhile(predicate.negate());
}
@Override
public CharSeq takeWhile(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
final StringBuilder sb = new StringBuilder();
for (int i = 0; i < length(); i++) {
char c = back.charAt(i);
if (!predicate.test(c)) {
break;
}
sb.append(c);
}
return sb.length() == length() ? this : sb.length() == 0 ? EMPTY : of(sb.toString());
}
/**
* Transforms this {@code CharSeq}.
*
* @param f A transformation
* @param Type of transformation result
* @return An instance of type {@code U}
* @throws NullPointerException if {@code f} is null
*/
public U transform(Function f) {
Objects.requireNonNull(f, "f is null");
return f.apply(this);
}
@Override
public IndexedSeq unit(Iterable iterable) {
return Vector.ofAll(iterable);
}
@Override
public Tuple2, IndexedSeq> unzip(
Function> unzipper) {
Objects.requireNonNull(unzipper, "unzipper is null");
IndexedSeq xs = Vector.empty();
IndexedSeq ys = Vector.empty();
for (int i = 0; i < length(); i++) {
final Tuple2 t = unzipper.apply(back.charAt(i));
xs = xs.append(t._1);
ys = ys.append(t._2);
}
return Tuple.of(xs, ys);
}
@Override
public Tuple3, IndexedSeq, IndexedSeq> unzip3(
Function> unzipper) {
Objects.requireNonNull(unzipper, "unzipper is null");
IndexedSeq xs = Vector.empty();
IndexedSeq ys = Vector.empty();
IndexedSeq zs = Vector.empty();
for (int i = 0; i < length(); i++) {
final Tuple3 t = unzipper.apply(back.charAt(i));
xs = xs.append(t._1);
ys = ys.append(t._2);
zs = zs.append(t._3);
}
return Tuple.of(xs, ys, zs);
}
@Override
public CharSeq update(int index, Character element) {
if (index < 0) {
throw new IndexOutOfBoundsException("update(" + index + ")");
}
if (index >= length()) {
throw new IndexOutOfBoundsException("update(" + index + ")");
}
return of(back.substring(0, index) + element + back.substring(index + 1));
}
@Override
public IndexedSeq> zip(Iterable that) {
Objects.requireNonNull(that, "that is null");
IndexedSeq> result = Vector.empty();
Iterator list1 = iterator();
java.util.Iterator list2 = that.iterator();
while (list1.hasNext() && list2.hasNext()) {
result = result.append(Tuple.of(list1.next(), list2.next()));
}
return result;
}
@Override
public IndexedSeq> zipAll(Iterable that, Character thisElem, U thatElem) {
Objects.requireNonNull(that, "that is null");
IndexedSeq> result = Vector.empty();
Iterator list1 = iterator();
java.util.Iterator list2 = that.iterator();
while (list1.hasNext() || list2.hasNext()) {
final Character elem1 = list1.hasNext() ? list1.next() : thisElem;
final U elem2 = list2.hasNext() ? list2.next() : thatElem;
result = result.append(Tuple.of(elem1, elem2));
}
return result;
}
@Override
public IndexedSeq> zipWithIndex() {
IndexedSeq> result = Vector.empty();
for (int i = 0; i < length(); i++) {
result = result.append(Tuple.of(get(i), (long) i));
}
return result;
}
@Override
public Character get(int index) {
return back.charAt(index);
}
@Override
public int indexOf(Character element, int from) {
return back.indexOf(element, from);
}
@Override
public int lastIndexOf(Character element, int end) {
return back.lastIndexOf(element, end);
}
@Override
public Tuple2 splitAt(long n) {
if (n <= 0) {
return Tuple.of(EMPTY, this);
} else if (n >= length()) {
return Tuple.of(this, EMPTY);
} else {
return Tuple.of(of(back.substring(0, (int) n)), of(back.substring((int) n)));
}
}
@Override
public Tuple2 splitAt(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
if (isEmpty()) {
return Tuple.of(EMPTY, EMPTY);
}
final StringBuilder left = new StringBuilder();
for (int i = 0; i < length(); i++) {
Character t = get(i);
if (!predicate.test(t)) {
left.append(t);
} else {
break;
}
}
return splitByBuilder(left);
}
@Override
public Tuple2 splitAtInclusive(Predicate predicate) {
Objects.requireNonNull(predicate, "predicate is null");
if (isEmpty()) {
return Tuple.of(EMPTY, EMPTY);
}
final StringBuilder left = new StringBuilder();
for (int i = 0; i < length(); i++) {
Character t = get(i);
left.append(t);
if (predicate.test(t)) {
break;
}
}
return splitByBuilder(left);
}
@Override
public boolean startsWith(Iterable that, int offset) {
return startsWith(CharSeq.ofAll(that), offset);
}
@Override
public Character head() {
if (isEmpty()) {
throw new NoSuchElementException("head of empty string");
} else {
return back.charAt(0);
}
}
@Override
public boolean isEmpty() {
return back.isEmpty();
}
@Override
public boolean isTraversableAgain() {
return true;
}
private Object readResolve() {
return isEmpty() ? EMPTY : this;
}
@Override
public boolean equals(Object o) {
if (o == this) {
return true;
} else if (o instanceof CharSeq) {
return ((CharSeq) o).back.equals(back);
} else {
return false;
}
}
@Override
public int hashCode() {
return back.hashCode();
}
//
//
// java.lang.CharSequence
//
//
/**
* Returns the {@code char} value at the
* specified index. An index ranges from {@code 0} to
* {@code length() - 1}. The first {@code char} value of the sequence
* is at index {@code 0}, the next at index {@code 1},
* and so on, as for array indexing.
*
* If the {@code char} value specified by the index is a
* surrogate, the surrogate
* value is returned.
*
* @param index the index of the {@code char} value.
* @return the {@code char} value at the specified index of this string.
* The first {@code char} value is at index {@code 0}.
* @throws IndexOutOfBoundsException if the {@code index}
* argument is negative or not less than the length of this
* string.
*/
@Override
public char charAt(int index) {
return back.charAt(index);
}
/**
* Returns the length of this string.
* The length is equal to the number of Unicode
* code units in the string.
*
* @return the length of the sequence of characters represented by this
* object.
*/
@Override
public int length() {
return back.length();
}
//
//
// String
//
//
/**
* Returns the character (Unicode code point) at the specified
* index. The index refers to {@code char} values
* (Unicode code units) and ranges from {@code 0} to
* {@link #length()}{@code - 1}.
*
*
If the {@code char} value specified at the given index
* is in the high-surrogate range, the following index is less
* than the length of this {@code CharSeq}, and the
* {@code char} value at the following index is in the
* low-surrogate range, then the supplementary code point
* corresponding to this surrogate pair is returned. Otherwise,
* the {@code char} value at the given index is returned.
*
* @param index the index to the {@code char} values
* @return the code point value of the character at the
* {@code index}
* @throws IndexOutOfBoundsException if the {@code index}
* argument is negative or not less than the length of this
* string.
*/
public int codePointAt(int index) {
return back.codePointAt(index);
}
/**
* Returns the character (Unicode code point) before the specified
* index. The index refers to {@code char} values
* (Unicode code units) and ranges from {@code 1} to {@link
* CharSequence#length() length}.
*
*
If the {@code char} value at {@code (index - 1)}
* is in the low-surrogate range, {@code (index - 2)} is not
* negative, and the {@code char} value at {@code (index -
* 2)} is in the high-surrogate range, then the
* supplementary code point value of the surrogate pair is
* returned. If the {@code char} value at {@code index -
* 1} is an unpaired low-surrogate or a high-surrogate, the
* surrogate value is returned.
*
* @param index the index following the code point that should be returned
* @return the Unicode code point value before the given index.
* @throws IndexOutOfBoundsException if the {@code index}
* argument is less than 1 or greater than the length
* of this string.
*/
public int codePointBefore(int index) {
return back.codePointBefore(index);
}
/**
* Returns the number of Unicode code points in the specified text
* range of this {@code CharSeq}. The text range begins at the
* specified {@code beginIndex} and extends to the
* {@code char} at index {@code endIndex - 1}. Thus the
* length (in {@code char}s) of the text range is
* {@code endIndex-beginIndex}. Unpaired surrogates within
* the text range count as one code point each.
*
* @param beginIndex the index to the first {@code char} of
* the text range.
* @param endIndex the index after the last {@code char} of
* the text range.
* @return the number of Unicode code points in the specified text
* range
* @throws IndexOutOfBoundsException if the
* {@code beginIndex} is negative, or {@code endIndex}
* is larger than the length of this {@code CharSeq}, or
* {@code beginIndex} is larger than {@code endIndex}.
*/
public int codePointCount(int beginIndex, int endIndex) {
return back.codePointCount(beginIndex, endIndex);
}
/**
* Returns the index within this {@code CharSeq} that is
* offset from the given {@code index} by
* {@code codePointOffset} code points. Unpaired surrogates
* within the text range given by {@code index} and
* {@code codePointOffset} count as one code point each.
*
* @param index the index to be offset
* @param codePointOffset the offset in code points
* @return the index within this {@code CharSeq}
* @throws IndexOutOfBoundsException if {@code index}
* is negative or larger then the length of this
* {@code CharSeq}, or if {@code codePointOffset} is positive
* and the substring starting with {@code index} has fewer
* than {@code codePointOffset} code points,
* or if {@code codePointOffset} is negative and the substring
* before {@code index} has fewer than the absolute value
* of {@code codePointOffset} code points.
*/
public int offsetByCodePoints(int index, int codePointOffset) {
return back.offsetByCodePoints(index, codePointOffset);
}
/**
* Copies characters from this string into the destination character
* array.
*
* The first character to be copied is at index {@code srcBegin};
* the last character to be copied is at index {@code srcEnd-1}
* (thus the total number of characters to be copied is
* {@code srcEnd-srcBegin}). The characters are copied into the
* subarray of {@code dst} starting at index {@code dstBegin}
* and ending at index:
*
* dstbegin + (srcEnd-srcBegin) - 1
*
*
* @param srcBegin index of the first character in the string
* to copy.
* @param srcEnd index after the last character in the string
* to copy.
* @param dst the destination array.
* @param dstBegin the start offset in the destination array.
* @throws IndexOutOfBoundsException If any of the following
* is true:
* - {@code srcBegin} is negative.
*
- {@code srcBegin} is greater than {@code srcEnd}
*
- {@code srcEnd} is greater than the length of this
* string
*
- {@code dstBegin} is negative
*
- {@code dstBegin+(srcEnd-srcBegin)} is larger than
* {@code dst.length}
*/
public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) {
back.getChars(srcBegin, srcEnd, dst, dstBegin);
}
/**
* Encodes this {@code CharSeq} into a sequence of bytes using the named
* charset, storing the result into a new byte array.
*
* The behavior of this method when this string cannot be encoded in
* the given charset is unspecified. The {@link
* java.nio.charset.CharsetEncoder} class should be used when more control
* over the encoding process is required.
*
* @param charsetName The name of a supported {@linkplain java.nio.charset.Charset
* charset}
* @return The resultant byte array
* @throws UnsupportedEncodingException If the named charset is not supported
*/
public byte[] getBytes(String charsetName) throws UnsupportedEncodingException {
return back.getBytes(charsetName);
}
/**
* Encodes this {@code CharSeq} into a sequence of bytes using the given
* {@linkplain java.nio.charset.Charset charset}, storing the result into a
* new byte array.
*
*
This method always replaces malformed-input and unmappable-character
* sequences with this charset's default replacement byte array. The
* {@link java.nio.charset.CharsetEncoder} class should be used when more
* control over the encoding process is required.
*
* @param charset The {@linkplain java.nio.charset.Charset} to be used to encode
* the {@code CharSeq}
* @return The resultant byte array
*/
public byte[] getBytes(Charset charset) {
return back.getBytes(charset);
}
/**
* Encodes this {@code CharSeq} into a sequence of bytes using the
* platform's default charset, storing the result into a new byte array.
*
*
The behavior of this method when this string cannot be encoded in
* the default charset is unspecified. The {@link
* java.nio.charset.CharsetEncoder} class should be used when more control
* over the encoding process is required.
*
* @return The resultant byte array
*/
public byte[] getBytes() {
return back.getBytes();
}
/**
* Compares this string to the specified {@code StringBuffer}. The result
* is {@code true} if and only if this {@code CharSeq} represents the same
* sequence of characters as the specified {@code StringBuffer}. This method
* synchronizes on the {@code StringBuffer}.
*
* @param sb The {@code StringBuffer} to compare this {@code CharSeq} against
* @return {@code true} if this {@code CharSeq} represents the same
* sequence of characters as the specified {@code StringBuffer},
* {@code false} otherwise
*/
public boolean contentEquals(StringBuffer sb) {
return back.contentEquals(sb);
}
/**
* Compares this string to the specified {@code CharSequence}. The
* result is {@code true} if and only if this {@code CharSeq} represents the
* same sequence of char values as the specified sequence. Note that if the
* {@code CharSequence} is a {@code StringBuffer} then the method
* synchronizes on it.
*
* @param cs The sequence to compare this {@code CharSeq} against
* @return {@code true} if this {@code CharSeq} represents the same
* sequence of char values as the specified sequence, {@code
* false} otherwise
*/
public boolean contentEquals(CharSequence cs) {
return back.contentEquals(cs);
}
/**
* Compares this {@code CharSeq} to another {@code CharSeq}, ignoring case
* considerations. Two strings are considered equal ignoring case if they
* are of the same length and corresponding characters in the two strings
* are equal ignoring case.
*
*
Two characters {@code c1} and {@code c2} are considered the same
* ignoring case if at least one of the following is true:
*
* - The two characters are the same (as compared by the
* {@code ==} operator)
*
- Applying the method {@link
* java.lang.Character#toUpperCase(char)} to each character
* produces the same result
*
- Applying the method {@link
* java.lang.Character#toLowerCase(char)} to each character
* produces the same result
*
*
* @param anotherString The {@code CharSeq} to compare this {@code CharSeq} against
* @return {@code true} if the argument is not {@code null} and it
* represents an equivalent {@code CharSeq} ignoring case; {@code
* false} otherwise
* @see #equals(Object)
*/
public boolean equalsIgnoreCase(CharSeq anotherString) {
return back.equalsIgnoreCase(anotherString.back);
}
/**
* Compares two strings lexicographically.
* The comparison is based on the Unicode value of each character in
* the strings. The character sequence represented by this
* {@code CharSeq} object is compared lexicographically to the
* character sequence represented by the argument string. The result is
* a negative integer if this {@code CharSeq} object
* lexicographically precedes the argument string. The result is a
* positive integer if this {@code CharSeq} object lexicographically
* follows the argument string. The result is zero if the strings
* are equal; {@code compareTo} returns {@code 0} exactly when
* the {@link #equals(Object)} method would return {@code true}.
*
* This is the definition of lexicographic ordering. If two strings are
* different, then either they have different characters at some index
* that is a valid index for both strings, or their lengths are different,
* or both. If they have different characters at one or more index
* positions, let k be the smallest such index; then the string
* whose character at position k has the smaller value, as
* determined by using the < operator, lexicographically precedes the
* other string. In this case, {@code compareTo} returns the
* difference of the two character values at position {@code k} in
* the two string -- that is, the value:
*
* this.charAt(k)-anotherString.charAt(k)
*
* If there is no index position at which they differ, then the shorter
* string lexicographically precedes the longer string. In this case,
* {@code compareTo} returns the difference of the lengths of the
* strings -- that is, the value:
*
* this.length()-anotherString.length()
*
*
* @param anotherString the {@code CharSeq} to be compared.
* @return the value {@code 0} if the argument string is equal to
* this string; a value less than {@code 0} if this string
* is lexicographically less than the string argument; and a
* value greater than {@code 0} if this string is
* lexicographically greater than the string argument.
*/
public int compareTo(CharSeq anotherString) {
return back.compareTo(anotherString.back);
}
/**
* Compares two strings lexicographically, ignoring case
* differences. This method returns an integer whose sign is that of
* calling {@code compareTo} with normalized versions of the strings
* where case differences have been eliminated by calling
* {@code Character.toLowerCase(Character.toUpperCase(character))} on
* each character.
*
* Note that this method does not take locale into account,
* and will result in an unsatisfactory ordering for certain locales.
* The java.text package provides collators to allow
* locale-sensitive ordering.
*
* @param str the {@code CharSeq} to be compared.
* @return a negative integer, zero, or a positive integer as the
* specified String is greater than, equal to, or less
* than this String, ignoring case considerations.
*/
public int compareToIgnoreCase(CharSeq str) {
return back.compareToIgnoreCase(str.back);
}
/**
* Tests if two string regions are equal.
*
* A substring of this {@code CharSeq} object is compared to a substring
* of the argument other. The result is true if these substrings
* represent identical character sequences. The substring of this
* {@code CharSeq} object to be compared begins at index {@code toffset}
* and has length {@code len}. The substring of other to be compared
* begins at index {@code ooffset} and has length {@code len}. The
* result is {@code false} if and only if at least one of the following
* is true:
*
- {@code toffset} is negative.
*
- {@code ooffset} is negative.
*
- {@code toffset+len} is greater than the length of this
* {@code CharSeq} object.
*
- {@code ooffset+len} is greater than the length of the other
* argument.
*
- There is some nonnegative integer k less than {@code len}
* such that:
* {@code this.charAt(toffset + }k{@code ) != other.charAt(ooffset + }
* k{@code )}
*
*
* @param toffset the starting offset of the subregion in this string.
* @param other the string argument.
* @param ooffset the starting offset of the subregion in the string
* argument.
* @param len the number of characters to compare.
* @return {@code true} if the specified subregion of this string
* exactly matches the specified subregion of the string argument;
* {@code false} otherwise.
*/
public boolean regionMatches(int toffset, CharSeq other, int ooffset, int len) {
return back.regionMatches(toffset, other.back, ooffset, len);
}
/**
* Tests if two string regions are equal.
*
* A substring of this {@code CharSeq} object is compared to a substring
* of the argument {@code other}. The result is {@code true} if these
* substrings represent character sequences that are the same, ignoring
* case if and only if {@code ignoreCase} is true. The substring of
* this {@code CharSeq} object to be compared begins at index
* {@code toffset} and has length {@code len}. The substring of
* {@code other} to be compared begins at index {@code ooffset} and
* has length {@code len}. The result is {@code false} if and only if
* at least one of the following is true:
*
- {@code toffset} is negative.
*
- {@code ooffset} is negative.
*
- {@code toffset+len} is greater than the length of this
* {@code CharSeq} object.
*
- {@code ooffset+len} is greater than the length of the other
* argument.
*
- {@code ignoreCase} is {@code false} and there is some nonnegative
* integer k less than {@code len} such that:
*
* this.charAt(toffset+k) != other.charAt(ooffset+k)
*
* - {@code ignoreCase} is {@code true} and there is some nonnegative
* integer k less than {@code len} such that:
*
* Character.toLowerCase(this.charAt(toffset+k)) !=
* Character.toLowerCase(other.charAt(ooffset+k))
*
* and:
*
* Character.toUpperCase(this.charAt(toffset+k)) !=
* Character.toUpperCase(other.charAt(ooffset+k))
*
*
*
* @param ignoreCase if {@code true}, ignore case when comparing
* characters.
* @param toffset the starting offset of the subregion in this
* string.
* @param other the string argument.
* @param ooffset the starting offset of the subregion in the string
* argument.
* @param len the number of characters to compare.
* @return {@code true} if the specified subregion of this string
* matches the specified subregion of the string argument;
* {@code false} otherwise. Whether the matching is exact
* or case insensitive depends on the {@code ignoreCase}
* argument.
*/
public boolean regionMatches(boolean ignoreCase, int toffset, CharSeq other, int ooffset, int len) {
return back.regionMatches(ignoreCase, toffset, other.back, ooffset, len);
}
@Override
public CharSeq subSequence(int beginIndex, int endIndex) {
if (beginIndex < 0) {
throw new IndexOutOfBoundsException("begin index " + beginIndex + " < 0");
}
if (endIndex > length()) {
throw new IndexOutOfBoundsException("endIndex " + endIndex + " > length " + length());
}
int subLen = endIndex - beginIndex;
if (subLen < 0) {
throw new IndexOutOfBoundsException("beginIndex " + beginIndex + " > endIndex " + endIndex);
}
if (beginIndex == 0 && endIndex == length()) {
return this;
} else {
return CharSeq.of(back.subSequence(beginIndex, endIndex));
}
}
/**
* Tests if the substring of this string beginning at the
* specified index starts with the specified prefix.
*
* @param prefix the prefix.
* @param toffset where to begin looking in this string.
* @return {@code true} if the character sequence represented by the
* argument is a prefix of the substring of this object starting
* at index {@code toffset}; {@code false} otherwise.
* The result is {@code false} if {@code toffset} is
* negative or greater than the length of this
* {@code CharSeq} object; otherwise the result is the same
* as the result of the expression
*
* this.substring(toffset).startsWith(prefix)
*
*/
public boolean startsWith(CharSeq prefix, int toffset) {
return back.startsWith(prefix.back, toffset);
}
/**
* Tests if this string starts with the specified prefix.
*
* @param prefix the prefix.
* @return {@code true} if the character sequence represented by the
* argument is a prefix of the character sequence represented by
* this string; {@code false} otherwise.
* Note also that {@code true} will be returned if the
* argument is an empty string or is equal to this
* {@code CharSeq} object as determined by the
* {@link #equals(Object)} method.
*/
public boolean startsWith(CharSeq prefix) {
return back.startsWith(prefix.back);
}
/**
* Tests if this string ends with the specified suffix.
*
* @param suffix the suffix.
* @return {@code true} if the character sequence represented by the
* argument is a suffix of the character sequence represented by
* this object; {@code false} otherwise. Note that the
* result will be {@code true} if the argument is the
* empty string or is equal to this {@code CharSeq} object
* as determined by the {@link #equals(Object)} method.
*/
public boolean endsWith(CharSeq suffix) {
return back.endsWith(suffix.back);
}
/**
* Returns the index within this string of the first occurrence of
* the specified character. If a character with value
* {@code ch} occurs in the character sequence represented by
* this {@code CharSeq} object, then the index (in Unicode
* code units) of the first such occurrence is returned. For
* values of {@code ch} in the range from 0 to 0xFFFF
* (inclusive), this is the smallest value k such that:
*
* this.charAt(k) == ch
*
* is true. For other values of {@code ch}, it is the
* smallest value k such that:
*
* this.codePointAt(k) == ch
*
* is true. In either case, if no such character occurs in this
* string, then {@code -1} is returned.
*
* @param ch a character (Unicode code point).
* @return the index of the first occurrence of the character in the
* character sequence represented by this object, or
* {@code -1} if the character does not occur.
*/
public int indexOf(int ch) {
return back.indexOf(ch);
}
/**
* Returns the index within this string of the first occurrence of the
* specified character, starting the search at the specified index.
*
* If a character with value {@code ch} occurs in the
* character sequence represented by this {@code CharSeq}
* object at an index no smaller than {@code fromIndex}, then
* the index of the first such occurrence is returned. For values
* of {@code ch} in the range from 0 to 0xFFFF (inclusive),
* this is the smallest value k such that:
*
* (this.charAt(k) == ch) {@code &&} (k >= fromIndex)
*
* is true. For other values of {@code ch}, it is the
* smallest value k such that:
*
* (this.codePointAt(k) == ch) {@code &&} (k >= fromIndex)
*
* is true. In either case, if no such character occurs in this
* string at or after position {@code fromIndex}, then
* {@code -1} is returned.
*
*
* There is no restriction on the value of {@code fromIndex}. If it
* is negative, it has the same effect as if it were zero: this entire
* string may be searched. If it is greater than the length of this
* string, it has the same effect as if it were equal to the length of
* this string: {@code -1} is returned.
*
*
All indices are specified in {@code char} values
* (Unicode code units).
*
* @param ch a character (Unicode code point).
* @param fromIndex the index to start the search from.
* @return the index of the first occurrence of the character in the
* character sequence represented by this object that is greater
* than or equal to {@code fromIndex}, or {@code -1}
* if the character does not occur.
*/
public int indexOf(int ch, int fromIndex) {
return back.indexOf(ch, fromIndex);
}
/**
* Returns the index within this string of the last occurrence of
* the specified character. For values of {@code ch} in the
* range from 0 to 0xFFFF (inclusive), the index (in Unicode code
* units) returned is the largest value k such that:
*
* this.charAt(k) == ch
*
* is true. For other values of {@code ch}, it is the
* largest value k such that:
*
* this.codePointAt(k) == ch
*
* is true. In either case, if no such character occurs in this
* string, then {@code -1} is returned. The
* {@code CharSeq} is searched backwards starting at the last
* character.
*
* @param ch a character (Unicode code point).
* @return the index of the last occurrence of the character in the
* character sequence represented by this object, or
* {@code -1} if the character does not occur.
*/
public int lastIndexOf(int ch) {
return back.lastIndexOf(ch);
}
/**
* Returns the index within this string of the last occurrence of
* the specified character, searching backward starting at the
* specified index. For values of {@code ch} in the range
* from 0 to 0xFFFF (inclusive), the index returned is the largest
* value k such that:
*
* (this.charAt(k) == ch) {@code &&} (k <= fromIndex)
*
* is true. For other values of {@code ch}, it is the
* largest value k such that:
*
* (this.codePointAt(k) == ch) {@code &&} (k <= fromIndex)
*
* is true. In either case, if no such character occurs in this
* string at or before position {@code fromIndex}, then
* {@code -1} is returned.
*
* All indices are specified in {@code char} values
* (Unicode code units).
*
* @param ch a character (Unicode code point).
* @param fromIndex the index to start the search from. There is no
* restriction on the value of {@code fromIndex}. If it is
* greater than or equal to the length of this string, it has
* the same effect as if it were equal to one less than the
* length of this string: this entire string may be searched.
* If it is negative, it has the same effect as if it were -1:
* -1 is returned.
* @return the index of the last occurrence of the character in the
* character sequence represented by this object that is less
* than or equal to {@code fromIndex}, or {@code -1}
* if the character does not occur before that point.
*/
public int lastIndexOf(int ch, int fromIndex) {
return back.lastIndexOf(ch, fromIndex);
}
/**
* Returns the index within this string of the first occurrence of the
* specified substring.
*
*
The returned index is the smallest value k for which:
*
* this.startsWith(str, k)
*
* If no such value of k exists, then {@code -1} is returned.
*
* @param str the substring to search for.
* @return the index of the first occurrence of the specified substring,
* or {@code -1} if there is no such occurrence.
*/
public int indexOf(CharSeq str) {
return back.indexOf(str.back);
}
/**
* Returns the index within this string of the first occurrence of the
* specified substring, starting at the specified index.
*
* The returned index is the smallest value k for which:
*
* k >= fromIndex {@code &&} this.startsWith(str, k)
*
* If no such value of k exists, then {@code -1} is returned.
*
* @param str the substring to search for.
* @param fromIndex the index from which to start the search.
* @return the index of the first occurrence of the specified substring,
* starting at the specified index,
* or {@code -1} if there is no such occurrence.
*/
public int indexOf(CharSeq str, int fromIndex) {
return back.indexOf(str.back, fromIndex);
}
/**
* Returns the index within this string of the last occurrence of the
* specified substring. The last occurrence of the empty string ""
* is considered to occur at the index value {@code this.length()}.
*
* The returned index is the largest value k for which:
*
* this.startsWith(str, k)
*
* If no such value of k exists, then {@code -1} is returned.
*
* @param str the substring to search for.
* @return the index of the last occurrence of the specified substring,
* or {@code -1} if there is no such occurrence.
*/
public int lastIndexOf(CharSeq str) {
return back.lastIndexOf(str.back);
}
/**
* Returns the index within this string of the last occurrence of the
* specified substring, searching backward starting at the specified index.
*
* The returned index is the largest value k for which:
*
* k {@code <=} fromIndex {@code &&} this.startsWith(str, k)
*
* If no such value of k exists, then {@code -1} is returned.
*
* @param str the substring to search for.
* @param fromIndex the index to start the search from.
* @return the index of the last occurrence of the specified substring,
* searching backward from the specified index,
* or {@code -1} if there is no such occurrence.
*/
public int lastIndexOf(CharSeq str, int fromIndex) {
return back.lastIndexOf(str.back, fromIndex);
}
/**
* Returns a string that is a substring of this string. The
* substring begins with the character at the specified index and
* extends to the end of this string.
* Examples:
*
* "unhappy".substring(2) returns "happy"
* "Harbison".substring(3) returns "bison"
* "emptiness".substring(9) returns "" (an empty string)
*
*
* @param beginIndex the beginning index, inclusive.
* @return the specified substring.
* @throws IndexOutOfBoundsException if
* {@code beginIndex} is negative or larger than the
* length of this {@code CharSeq} object.
*/
public CharSeq substring(int beginIndex) {
return CharSeq.of(back.substring(beginIndex));
}
/**
* Returns a string that is a substring of this string. The
* substring begins at the specified {@code beginIndex} and
* extends to the character at index {@code endIndex - 1}.
* Thus the length of the substring is {@code endIndex-beginIndex}.
*
* Examples:
*
* "hamburger".substring(4, 8) returns "urge"
* "smiles".substring(1, 5) returns "mile"
*
*
* @param beginIndex the beginning index, inclusive.
* @param endIndex the ending index, exclusive.
* @return the specified substring.
* @throws IndexOutOfBoundsException if the
* {@code beginIndex} is negative, or
* {@code endIndex} is larger than the length of
* this {@code CharSeq} object, or
* {@code beginIndex} is larger than
* {@code endIndex}.
*/
public CharSeq substring(int beginIndex, int endIndex) {
return CharSeq.of(back.substring(beginIndex, endIndex));
}
@Override
public String stringPrefix() {
return "CharSeq";
}
/**
* Returns a string containing the characters in this sequence in the same
* order as this sequence. The length of the string will be the length of
* this sequence.
*
* @return a string consisting of exactly this sequence of characters
*/
@Override
public String toString() {
return back;
}
/**
* Concatenates the specified string to the end of this string.
*
* If the length of the argument string is {@code 0}, then this
* {@code CharSeq} object is returned. Otherwise, a
* {@code CharSeq} object is returned that represents a character
* sequence that is the concatenation of the character sequence
* represented by this {@code CharSeq} object and the character
* sequence represented by the argument string.
* Examples:
*
* "cares".concat("s") returns "caress"
* "to".concat("get").concat("her") returns "together"
*
*
* @param str the {@code CharSeq} that is concatenated to the end
* of this {@code CharSeq}.
* @return a string that represents the concatenation of this object's
* characters followed by the string argument's characters.
*/
public CharSeq concat(CharSeq str) {
return CharSeq.of(back.concat(str.back));
}
/**
* Tells whether or not this string matches the given regular expression.
*
* An invocation of this method of the form
* str{@code .matches(}regex{@code )} yields exactly the
* same result as the expression
*
*
* {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#matches(String, CharSequence)
* matches(regex, str)}
*
*
* @param regex the regular expression to which this string is to be matched
* @return {@code true} if, and only if, this string matches the
* given regular expression
* @throws PatternSyntaxException if the regular expression's syntax is invalid
* @see java.util.regex.Pattern
*/
public boolean matches(String regex) {
return back.matches(regex);
}
/**
* Returns true if and only if this string contains the specified
* sequence of char values.
*
* @param s the sequence to search for
* @return true if this string contains {@code s}, false otherwise
*/
public boolean contains(CharSequence s) {
return back.contains(s);
}
/**
* Replaces the first substring of this string that matches the given regular expression with the
* given replacement.
*
* An invocation of this method of the form
* str{@code .replaceFirst(}regex{@code ,} repl{@code )}
* yields exactly the same result as the expression
*
*
*
* {@link java.util.regex.Pattern}.{@link
* java.util.regex.Pattern#compile compile}(regex).{@link
* java.util.regex.Pattern#matcher(java.lang.CharSequence) matcher}(str).{@link
* java.util.regex.Matcher#replaceFirst replaceFirst}(repl)
*
*
*
*
* Note that backslashes ({@code \}) and dollar signs ({@code $}) in the
* replacement string may cause the results to be different than if it were
* being treated as a literal replacement string; see
* {@link java.util.regex.Matcher#replaceFirst}.
* Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
* meaning of these characters, if desired.
*
* @param regex the regular expression to which this string is to be matched
* @param replacement the string to be substituted for the first match
* @return The resulting {@code CharSeq}
* @throws PatternSyntaxException if the regular expression's syntax is invalid
* @see java.util.regex.Pattern
*/
public CharSeq replaceFirst(String regex, String replacement) {
return CharSeq.of(back.replaceFirst(regex, replacement));
}
/**
* Replaces each substring of this string that matches the given regular expression with the
* given replacement.
*
*
An invocation of this method of the form
* str{@code .replaceAll(}regex{@code ,} repl{@code )}
* yields exactly the same result as the expression
*
*
*
* {@link java.util.regex.Pattern}.{@link
* java.util.regex.Pattern#compile compile}(regex).{@link
* java.util.regex.Pattern#matcher(java.lang.CharSequence) matcher}(str).{@link
* java.util.regex.Matcher#replaceAll replaceAll}(repl)
*
*
*
*
* Note that backslashes ({@code \}) and dollar signs ({@code $}) in the
* replacement string may cause the results to be different than if it were
* being treated as a literal replacement string; see
* {@link java.util.regex.Matcher#replaceAll Matcher.replaceAll}.
* Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
* meaning of these characters, if desired.
*
* @param regex the regular expression to which this string is to be matched
* @param replacement the string to be substituted for each match
* @return The resulting {@code CharSeq}
* @throws PatternSyntaxException if the regular expression's syntax is invalid
* @see java.util.regex.Pattern
*/
public CharSeq replaceAll(String regex, String replacement) {
return CharSeq.of(back.replaceAll(regex, replacement));
}
/**
* Replaces each substring of this string that matches the literal target
* sequence with the specified literal replacement sequence. The
* replacement proceeds from the beginning of the string to the end, for
* example, replacing "aa" with "b" in the string "aaa" will result in
* "ba" rather than "ab".
*
* @param target The sequence of char values to be replaced
* @param replacement The replacement sequence of char values
* @return The resulting string
*/
public CharSeq replace(CharSequence target, CharSequence replacement) {
return CharSeq.of(back.replace(target, replacement));
}
/**
* Splits this string around matches of the given
* regular expression.
*
*
The array returned by this method contains each substring of this
* string that is terminated by another substring that matches the given
* expression or is terminated by the end of the string. The substrings in
* the array are in the order in which they occur in this string. If the
* expression does not match any part of the input then the resulting array
* has just one element, namely this string.
*
*
When there is a positive-width match at the beginning of this
* string then an empty leading substring is included at the beginning
* of the resulting array. A zero-width match at the beginning however
* never produces such empty leading substring.
*
*
The {@code limit} parameter controls the number of times the
* pattern is applied and therefore affects the length of the resulting
* array. If the limit n is greater than zero then the pattern
* will be applied at most n - 1 times, the array's
* length will be no greater than n, and the array's last entry
* will contain all input beyond the last matched delimiter. If n
* is non-positive then the pattern will be applied as many times as
* possible and the array can have any length. If n is zero then
* the pattern will be applied as many times as possible, the array can
* have any length, and trailing empty strings will be discarded.
*
*
The string {@code "boo:and:foo"}, for example, yields the
* following results with these parameters:
*
*
*
* Regex
* Limit
* Result
*
* :
* 2
* {@code { "boo", "and:foo" }} :
* 5
* {@code { "boo", "and", "foo" }} :
* -2
* {@code { "boo", "and", "foo" }} o
* 5
* {@code { "b", "", ":and:f", "", "" }} o
* -2
* {@code { "b", "", ":and:f", "", "" }} o
* 0
* {@code { "b", "", ":and:f" }}
*
* An invocation of this method of the form
* str.{@code split(}regex{@code ,} n{@code )}
* yields the same result as the expression
*
*
*
* {@link java.util.regex.Pattern}.{@link
* java.util.regex.Pattern#compile compile}(regex).{@link
* java.util.regex.Pattern#split(java.lang.CharSequence, int) split}(str, n)
*
*
*
* @param regex the delimiting regular expression
* @param limit the result threshold, as described above
* @return the array of strings computed by splitting this string
* around matches of the given regular expression
* @throws PatternSyntaxException if the regular expression's syntax is invalid
* @see java.util.regex.Pattern
*/
public CharSeq[] split(String regex, int limit) {
final String[] javaStrings = back.split(regex, limit);
final CharSeq[] strings = new CharSeq[javaStrings.length];
for (int i = 0; i < strings.length; i++) {
strings[i] = of(javaStrings[i]);
}
return strings;
}
/**
* Splits this string around matches of the given regular expression.
*
* This method works as if by invoking the two-argument {@link
* #split(String, int) split} method with the given expression and a limit
* argument of zero. Trailing empty strings are therefore not included in
* the resulting array.
*
*
The string {@code "boo:and:foo"}, for example, yields the following
* results with these expressions:
*
*
*
* Regex
* Result
*
* :
* {@code { "boo", "and", "foo" }} o
* {@code { "b", "", ":and:f" }}
*
* @param regex the delimiting regular expression
* @return the array of strings computed by splitting this string
* around matches of the given regular expression
* @throws PatternSyntaxException if the regular expression's syntax is invalid
* @see java.util.regex.Pattern
*/
public CharSeq[] split(String regex) {
return split(regex, 0);
}
/**
* Converts all of the characters in this {@code CharSeq} to lower
* case using the rules of the given {@code Locale}. Case mapping is based
* on the Unicode Standard version specified by the {@link java.lang.Character Character}
* class. Since case mappings are not always 1:1 char mappings, the resulting
* {@code CharSeq} may be a different length than the original {@code CharSeq}.
*
* Examples of lowercase mappings are in the following table:
*
*
* Language Code of Locale
* Upper Case
* Lower Case
* Description
*
*
* tr (Turkish)
* \u0130
* \u0069
* capital letter I with dot above -> small letter i
*
*
* tr (Turkish)
* \u0049
* \u0131
* capital letter I -> small letter dotless i
*
*
* (all)
* French Fries
* french fries
* lowercased all chars in String
*
*
* (all)
* 
* 
* 
* 
* 
lowercased all chars in String
*
*
*
* @param locale use the case transformation rules for this locale
* @return the {@code CharSeq}, converted to lowercase.
* @see String#toLowerCase()
* @see String#toUpperCase()
* @see String#toUpperCase(Locale)
*/
public CharSeq toLowerCase(Locale locale) {
return CharSeq.of(back.toLowerCase(locale));
}
/**
* Converts all of the characters in this {@code CharSeq} to lower
* case using the rules of the default locale. This is equivalent to calling
* {@code toLowerCase(Locale.getDefault())}.
*
* Note: This method is locale sensitive, and may produce unexpected
* results if used for strings that are intended to be interpreted locale
* independently.
* Examples are programming language identifiers, protocol keys, and HTML
* tags.
* For instance, {@code "TITLE".toLowerCase()} in a Turkish locale
* returns {@code "t\u005Cu0131tle"}, where '\u005Cu0131' is the
* LATIN SMALL LETTER DOTLESS I character.
* To obtain correct results for locale insensitive strings, use
* {@code toLowerCase(Locale.ROOT)}.
*
*
* @return the {@code CharSeq}, converted to lowercase.
* @see String#toLowerCase(Locale)
*/
public CharSeq toLowerCase() {
return CharSeq.of(back.toLowerCase(Locale.getDefault()));
}
/**
* Converts all of the characters in this {@code CharSeq} to upper
* case using the rules of the given {@code Locale}. Case mapping is based
* on the Unicode Standard version specified by the {@link java.lang.Character Character}
* class. Since case mappings are not always 1:1 char mappings, the resulting
* {@code CharSeq} may be a different length than the original {@code CharSeq}.
*
* Examples of locale-sensitive and 1:M case mappings are in the following table.
*
*
*
* Language Code of Locale
* Lower Case
* Upper Case
* Description
*
*
* tr (Turkish)
* \u0069
* \u0130
* small letter i -> capital letter I with dot above
*
*
* tr (Turkish)
* \u0131
* \u0049
* small letter dotless i -> capital letter I
*
*
* (all)
* \u00df
* \u0053 \u0053
* small letter sharp s -> two letters: SS
*
*
* (all)
* Fahrvergnügen
* FAHRVERGNÜGEN
*
*
*
* @param locale use the case transformation rules for this locale
* @return the {@code CharSeq}, converted to uppercase.
* @see String#toUpperCase()
* @see String#toLowerCase()
* @see String#toLowerCase(Locale)
*/
public CharSeq toUpperCase(Locale locale) {
return CharSeq.of(back.toUpperCase(locale));
}
/**
* Converts all of the characters in this {@code CharSeq} to upper
* case using the rules of the default locale. This method is equivalent to
* {@code toUpperCase(Locale.getDefault())}.
*
* Note: This method is locale sensitive, and may produce unexpected
* results if used for strings that are intended to be interpreted locale
* independently.
* Examples are programming language identifiers, protocol keys, and HTML
* tags.
* For instance, {@code "title".toUpperCase()} in a Turkish locale
* returns {@code "T\u005Cu0130TLE"}, where '\u005Cu0130' is the
* LATIN CAPITAL LETTER I WITH DOT ABOVE character.
* To obtain correct results for locale insensitive strings, use
* {@code toUpperCase(Locale.ROOT)}.
*
*
* @return the {@code CharSeq}, converted to uppercase.
* @see String#toUpperCase(Locale)
*/
public CharSeq toUpperCase() {
return CharSeq.of(back.toUpperCase(Locale.getDefault()));
}
/**
* Returns a string whose value is this string, with any leading and trailing
* whitespace removed.
*
* If this {@code CharSeq} object represents an empty character
* sequence, or the first and last characters of character sequence
* represented by this {@code CharSeq} object both have codes
* greater than {@code '\u005Cu0020'} (the space character), then a
* reference to this {@code CharSeq} object is returned.
*
* Otherwise, if there is no character with a code greater than
* {@code '\u005Cu0020'} in the string, then a
* {@code CharSeq} object representing an empty string is
* returned.
*
* Otherwise, let k be the index of the first character in the
* string whose code is greater than {@code '\u005Cu0020'}, and let
* m be the index of the last character in the string whose code
* is greater than {@code '\u005Cu0020'}. A {@code CharSeq}
* object is returned, representing the substring of this string that
* begins with the character at index k and ends with the
* character at index m-that is, the result of
* {@code this.substring(k, m + 1)}.
*
* This method may be used to trim whitespace (as defined above) from
* the beginning and end of a string.
*
* @return A string whose value is this string, with any leading and trailing white
* space removed, or this string if it has no leading or
* trailing white space.
*/
public CharSeq trim() {
return of(back.trim());
}
/**
* Converts this string to a new character array.
*
* @return a newly allocated character array whose length is the length
* of this string and whose contents are initialized to contain
* the character sequence represented by this string.
*/
public char[] toCharArray() {
return back.toCharArray();
}
@FunctionalInterface
public interface CharUnaryOperator {
char apply(char c);
}
@FunctionalInterface
public interface CharFunction {
R apply(char c);
}
}
interface CharSeqModule {
interface Combinations {
static IndexedSeq apply(CharSeq elements, int k) {
if (k == 0) {
return Vector.of(CharSeq.empty());
} else {
return elements.zipWithIndex().flatMap(
t -> apply(elements.drop(t._2 + 1), (k - 1)).map((CharSeq c) -> c.prepend(t._1))
);
}
}
}
}